The present invention relates to an iron-based alloy powder wherein the alloy comprises the elements Fe (iron), Cr (chrome) and Mo (molybdenum) and the iron-based alloy powder is produced by an ultra-high liquid atomization process comprising at least two stages as defined below.

A titanium-free cobalt-chromium alloy for a powder, contains (in wt.%) C 0.40 -1.50%, Cr 24.0 - 32.0%, W 3.0 - 8.0%, Mo 0.1 - 5.0%, where 4.0 < W + Mo < 9.5 is satisfied by the content of W and Mo in wt.%, Nb max. 0.5%, Ta max. 0.5 %, where Nb + Ta < 0.8 is satisfied by the content of Nb and Ta in wt.%, Ni 0.005 - 25.0%, Fe 0.005 -15.0%, where Ni + Fe > 3.0 is satisfied by the content of Ni and Fe in wt.%, Mn 0.005 -5.0%, Al max. 0.5%, N 0.0005 - 0.15%, Si < 0.3%, Cu max. 0.4%, O 0.0001 - 0.1%, P max. 0.015%, B max. 0.015%, S max. 0.015%, residual Co, and impurities resulting from the production process, in particular Zr max. 0.03% and Ti max. 0.025%.

An Fe-based alloy for melting-solidification shaping including, in mass %: 18.0≤Co<25.0; 12.0≤Mo+W/2≤20.0; 0.2≤Mn≤5.0; 0.5≤Ni≤10.0; and 0≤Si≤1.0, with the balance being Fe and unavoidable impurities, and satisfying the following expressions (1) and (2) when [M] represents a content of an element M expressed in mass % basis, 58≤[Co]+3([Mo]+[W]/2)≤95 (1), A/B≥1.6 (2) where A=[Co]+[Ni]+3[Mn], and B=[Mo]+[W]/2+[Si], in which when the Fe-based alloy includes no Mo, the expressions (1) and (2) are calculated using [Mo]=0, when the Fe-based alloy includes no Si, the expression (2) is calculated using [Si]=0, and when the Fe-based alloy includes no W, the expressions (1) and (2) are calculated using [W]=0.

A powder production method includes providing at least one elongated member including a ductile material; providing a rotating or vibrating cutter configured to repeatedly cut an end of the at least one elongated member to produce particles; and advancing the at least one elongated member or the cutter towards the other of the at least one elongated member or the cutter to cut the particles from the at least one elongated member to produce a powder comprising a plurality of the particles. The particles produced by the method can have a diameter ranging from about 10 μm to about 200 μm.

A method for preparing the prefabricated crack defects includes defining a defect area, defining a volume percentage of the crack defects in the defect area, adjusting the proportion of spherical powder, the proportion of hollow powder and process parameters of defect preparation according to the volume percentage of the crack defects, based on the technique of laser melting deposition, printing the defect area layer by layer by using the defect preparation powder and the process parameters of defect preparation, wherein the particle size of the defect preparation powder is between 45 μm and 150 μm, the proportion of spherical powder≥93% and the proportion of hollow powder<0.5%, the process parameters of defect preparation including: laser power of 450W-550W, scanning rate of 600 mm/min-1200 mm/min, powder feeding rate of 4 g/min-12 g/min, spot diameter of 1 mm-1.2 mm, scanning spacing of 0.5 mm-0.8 mm and layer thickness of 0.08 mm-0.2 mm.

A method for preparing the prefabricated crack defects includes defining a defect area, defining a volume percentage of the crack defects in the defect area, adjusting the proportion of spherical powder, the proportion of hollow powder and process parameters of defect preparation according to the volume percentage of the crack defects, based on the technique of laser melting deposition, printing the defect area layer by layer by using the defect preparation powder and the process parameters of defect preparation, wherein the particle size of the defect preparation powder is between 45 μm and 150 μm, the proportion of spherical powder≥93% and the proportion of hollow powder<0.5%, the process parameters of defect preparation including: laser power of 450W-550W, scanning rate of 600 mm/min-1200 mm/min, powder feeding rate of 4 g/min-12 g/min, spot diameter of 1 mm-1.2 mm, scanning spacing of 0.5 mm-0.8 mm and layer thickness of 0.08 mm-0.2 mm.

A method for preparing prefabricated gas pore defects includes: defining a defect area, defining a volume percentage of the gas pore defects in the defect area, adjusting the proportion of satellite powder, the proportion of hollow powder and the process parameters of defect preparation according to the volume percentage of the gas pore defects, based on the technique of laser melting deposition, printing the defect area layer by layer by using the defect preparation powder and the process parameters of defect preparation, wherein the particle size of the defect preparation powder is between 45 μm and 106 μm, the proportion of satellite powder is 55-65% and the proportion of hollow powder is 2.9-3.1%, the process parameters of defect preparation comprises: laser power of 600W-1000W, scanning rate of 400 mm/min-800 mm/min, powder feeding rate of 12 g/min-20 g/min, spot diameter of 1 mm-2 mm, scanning spacing of 0.5 mm-1 mm and layer thickness of 0.15 mm-0.2 mm.

A method for preparing prefabricated gas pore defects includes: defining a defect area, defining a volume percentage of the gas pore defects in the defect area, adjusting the proportion of satellite powder, the proportion of hollow powder and the process parameters of defect preparation according to the volume percentage of the gas pore defects, based on the technique of laser melting deposition, printing the defect area layer by layer by using the defect preparation powder and the process parameters of defect preparation, wherein the particle size of the defect preparation powder is between 45 μm and 106 μm, the proportion of satellite powder is 55-65% and the proportion of hollow powder is 2.9-3.1%, the process parameters of defect preparation comprises: laser power of 600W-1000W, scanning rate of 400 mm/min-800 mm/min, powder feeding rate of 12 g/min-20 g/min, spot diameter of 1 mm-2 mm, scanning spacing of 0.5 mm-1 mm and layer thickness of 0.15 mm-0.2 mm.

Disclosed herein are embodiments of methods, devices, and assemblies for processing feedstock materials using microwave plasma processing. Specifically, the feedstock materials disclosed herein pertains to scrap materials, dehydrogenated or non-hydrogenated feed material, recycled used powder, and gas atomized powders. Microwave plasma processing can be used to spheroidize and remove contaminants. Advantageously, microwave plasma processed feedstock can be used in various applications such as additive manufacturing or powdered metallurgy (PM) applications that require high powder flowability.

Disclosed herein are embodiments of methods, devices, and assemblies for processing feedstock materials using microwave plasma processing. Specifically, the feedstock materials disclosed herein pertains to scrap materials, dehydrogenated or non-hydrogenated feed material, recycled used powder, and gas atomized powders. Microwave plasma processing can be used to spheroidize and remove contaminants. Advantageously, microwave plasma processed feedstock can be used in various applications such as additive manufacturing or powdered metallurgy (PM) applications that require high powder flowability.